Power supplies and ultracapacitor based battery simulator

Abstract

An ultracapacitor based power storage device suitable for use in hybrid fuel cell systems and other power systems includes circuitry for simulating the response of a battery. A voltage current limiting circuit may be employed with a variety of electrical storage devices, for example, ultracapacitors and batteries.

Description

[0001] 1. Field of the Invention[0002] This disclosure generally relates to power supplies, for example, fuel cell systems, and to electrical power storage devices, for example, batteries and / or ultracapacitors.[0003] 2. Description of the Related Art[0004] Fuel cells are known in the art. Fuel cells electrochemically react a fuel stream comprising hydrogen and an oxidant stream comprising oxygen to generate an electric current. Fuel cell electric power plants have been employed in transportation, portable and stationary applications. Electric power plants employing fuel cells as the sole source of power may have several disadvantages relating to the time it takes for the fuel cells to produce full power, and their surge demand capacity, for example.[0005] Fuel cell output is proportional to the amount of reactants supplied. On start-up, there is typically a delay until the fuel cells reach full operating power. For this reason, such power plants are inadequate for some applications...

AI Technical Summary

Problems solved by technology

Electric power plants employing fuel cells as the sole source of power may have several disadvantages relating to the time it takes for the fuel cells to produce full power, and their surge demand capacity, for example.

On start-up, there is typically a delay until the fuel cells reach full operating power.

For this reason, such power plants are inadequate for some applications because they are not "instant on".

While this approach improves response time, it exacerbates hydrogen storage issues by significantly increasing hydrogen consumption.

In addition, operational lifetime of the power plant may be adversely affected compared to systems where the power plant is operated intermittently.

Fuel cells can be damaged if the load requirements exceed their maximum output.

This, in turn, undesirably increases the cost of the power plant.

However, VRLA batteries are large and heavy.

Environmental regulations relating to the storage and operation of VRLA batteries also add to increased costs.

In certain applications, such as point-of-presence battery banks for back-up power and / or uninterruptible power supply systems (UPS), the use of VRLA batteries is less than desirable.

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